A typical retractable tape rule assembly includes an elongated metal rule blade that is mounted on a reel rotatably disposed within a housing assembly. The housing assembly includes two housing members that are held together with a plurality of fasteners. The blade is retracted into the housing assembly for storage by coiling it about the reel. A blade hook is provided on the free end of the blade. When the blade is fully retracted the blade hook is disposed at the housing assembly opening. The blade hook is usually made of sheet metal. The hook includes a hook portion that extends downwardly at an essentially right angle from a mounting portion of the hook that is mounted on the end of the blade. When the hook of the retracted blade is at the opening, the downwardly extending hook portion extends below a bottom end surface of the housing assembly adjacent the opening.
It is convenient for the user to have the hook portion of the blade extend below the bottom surface of the housing assembly, so that, for example, the retracted blade can be easily withdrawn from the housing assembly by grasping the hook portion or hooking the hook portion over an edge or corner of an object or workpiece. The hook aids the tape assembly user when taking a measurement by securing the free end of the blade while the measurement is taken. The hook is precisely manufactured and mounted to assure accurate measurements.
If the hook is damaged by being bent so that the hook portion is misshapen or no longer at an essentially right angle with the free end of the blade, a measurement read while securing the blade with the hook portion may not be accurate. Because a portion of the blade hook extends below the bottom end surface of the housing assembly when the blade is fully retracted, the hook is especially vulnerable to damage if the tape assembly is dropped or otherwise impacted when the blade is retracted. If the lower edge of the hook portion is impacted in a direction that causes the free end to move upwardly with respect to the housing assembly, the hook portion may permanently bend relative to the mounting portion if, during impact, the mounting portion of the hook is prevented by downwardly facing surfaces on the housing assembly that define the housing assembly opening from moving upwardly a sufficient distance with respect to the opening. Upper surfaces on the mounting portion of the hook contact downwardly facing surfaces on the housing assembly at the opening to limit the upward movement of the hook. Thus, the size of the opening, particularly the height of the opening, is critical in preventing damage to the blade hook during impact.
Heretofore, rule assembly opening height has been limited to an undesirably degree by rule assembly construction, particularly the location one of a plurality of fasteners used to hold the housing members of the housing assembly together and the location of a blade holding assembly used to releasably hold the blade in an extended position against the spring force provided by the coil spring. The blade holding assembly includes an arcuate locking member that is movable along an arcuate path between a normal inoperative position and a blade locking position. The blade holding assembly is generally disposed adjacent the reel and between the reel and the opening. The arcuate path followed by the locking member generally defines the interior of a bottom corner of the housing assembly adjacent the opening. An axially extending fastener (where "axially" refers to the direction of the axis of rotation of the reel) is generally provided in the corner of the housing assembly above the opening and between the arcuate locking member and a forward the facing wall surface of the housing assembly. Prior art housing assembly construction limits the height of the opening to an undesirable degree by providing housing assemblies that limit the distance the fastener can be position above the bottom of the housing opening.
A need exists for a tape assembly that provides an opening that is constructed and arranged to protect the hook from bending if the hook at the housing opening is impacted.